For some time now, our Java application has came pre bundled with a JRE on Windows. We have a little launcher app written in C that make the application use our pre bundled
While this reply is long after the initial question if may be of interest to others still searching for an answer.
I am on the development team of a small application called Pyxis Bundler that can bundle applications for OSX where the user can choose to include the JRE from their CLASSPATH, can select a specific JRE or none.
This application will generate a properly structured Mac Application Bundle, including icon and splash, and the user can even write the version number to the splash screen. In addition it can create a multi-resolution Apple Icon Image from a PNG file (to use as a modern ICNS file).
This is an easy to use GUI application where settings are automatically saved, making it easy to update applications.
The only prerequisite is that the developer uses proper package names. Single word package names are not allowed.
More information is available from https://explorepyxis.com
A free trial is available. Please drop an email to the company to request same.